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spi: npcm: add NPCM PSPI controller driver

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Add Nuvoton NPCM BMC Peripheral SPI controller driver.

Signed-off-by: Tomer Maimon <tmaimon77@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Tomer Maimon 2018-11-12 18:42:32 +02:00 committed by Mark Brown
parent 4ad26864df
commit 2a22f1b30c
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
3 changed files with 488 additions and 0 deletions
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7
drivers/spi/Kconfig
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@ -397,6 +397,13 @@ config SPI_MT65XX
say Y or M here.If you are not sure, say N.
SPI drivers for Mediatek MT65XX and MT81XX series ARM SoCs.
config SPI_NPCM_PSPI
tristate "Nuvoton NPCM PSPI Controller"
depends on ARCH_NPCM || COMPILE_TEST
help
This driver provides support for Nuvoton NPCM BMC
Peripheral SPI controller in master mode.
config SPI_NUC900
tristate "Nuvoton NUC900 series SPI"
depends on ARCH_W90X900

1
drivers/spi/Makefile
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@ -60,6 +60,7 @@ obj-$(CONFIG_SPI_MPC52xx) += spi-mpc52xx.o
obj-$(CONFIG_SPI_MT65XX) += spi-mt65xx.o
obj-$(CONFIG_SPI_MXIC) += spi-mxic.o
obj-$(CONFIG_SPI_MXS) += spi-mxs.o
obj-$(CONFIG_SPI_NPCM_PSPI) += spi-npcm-pspi.o
obj-$(CONFIG_SPI_NUC900) += spi-nuc900.o
obj-$(CONFIG_SPI_OC_TINY) += spi-oc-tiny.o
spi-octeon-objs := spi-cavium.o spi-cavium-octeon.o

480
drivers/spi/spi-npcm-pspi.c Normal file
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@ -0,0 +1,480 @@
// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2018 Nuvoton Technology corporation.
#include <linux/kernel.h>
#include <linux/bitfield.h>
#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/spi/spi.h>
#include <linux/gpio.h>
#include <linux/of_gpio.h>
#include <asm/unaligned.h>
#include <linux/regmap.h>
#include <linux/mfd/syscon.h>
struct npcm_pspi {
struct completion xfer_done;
struct regmap *rst_regmap;
struct spi_master *master;
unsigned int tx_bytes;
unsigned int rx_bytes;
void __iomem *base;
bool is_save_param;
u8 bits_per_word;
const u8 *tx_buf;
struct clk *clk;
u32 speed_hz;
u8 *rx_buf;
u16 mode;
u32 id;
};
#define DRIVER_NAME "npcm-pspi"
#define NPCM_PSPI_DATA 0x00
#define NPCM_PSPI_CTL1 0x02
#define NPCM_PSPI_STAT 0x04
/* definitions for control and status register */
#define NPCM_PSPI_CTL1_SPIEN BIT(0)
#define NPCM_PSPI_CTL1_MOD BIT(2)
#define NPCM_PSPI_CTL1_EIR BIT(5)
#define NPCM_PSPI_CTL1_EIW BIT(6)
#define NPCM_PSPI_CTL1_SCM BIT(7)
#define NPCM_PSPI_CTL1_SCIDL BIT(8)
#define NPCM_PSPI_CTL1_SCDV6_0 GENMASK(15, 9)
#define NPCM_PSPI_STAT_BSY BIT(0)
#define NPCM_PSPI_STAT_RBF BIT(1)
/* general definitions */
#define NPCM_PSPI_TIMEOUT_MS 2000
#define NPCM_PSPI_MAX_CLK_DIVIDER 256
#define NPCM_PSPI_MIN_CLK_DIVIDER 4
#define NPCM_PSPI_DEFAULT_CLK 25000000
/* reset register */
#define NPCM7XX_IPSRST2_OFFSET 0x24
#define NPCM7XX_PSPI1_RESET BIT(22)
#define NPCM7XX_PSPI2_RESET BIT(23)
static inline unsigned int bytes_per_word(unsigned int bits)
{
return bits <= 8 ? 1 : 2;
}
static inline void npcm_pspi_irq_enable(struct npcm_pspi *priv, u16 mask)
{
u16 val;
val = ioread16(priv->base + NPCM_PSPI_CTL1);
val |= mask;
iowrite16(val, priv->base + NPCM_PSPI_CTL1);
}
static inline void npcm_pspi_irq_disable(struct npcm_pspi *priv, u16 mask)
{
u16 val;
val = ioread16(priv->base + NPCM_PSPI_CTL1);
val &= ~mask;
iowrite16(val, priv->base + NPCM_PSPI_CTL1);
}
static inline void npcm_pspi_enable(struct npcm_pspi *priv)
{
u16 val;
val = ioread16(priv->base + NPCM_PSPI_CTL1);
val |= NPCM_PSPI_CTL1_SPIEN;
iowrite16(val, priv->base + NPCM_PSPI_CTL1);
}
static inline void npcm_pspi_disable(struct npcm_pspi *priv)
{
u16 val;
val = ioread16(priv->base + NPCM_PSPI_CTL1);
val &= ~NPCM_PSPI_CTL1_SPIEN;
iowrite16(val, priv->base + NPCM_PSPI_CTL1);
}
static void npcm_pspi_set_mode(struct spi_device *spi)
{
struct npcm_pspi *priv = spi_master_get_devdata(spi->master);
u16 regtemp;
u16 mode_val;
switch (spi->mode & (SPI_CPOL | SPI_CPHA)) {
case SPI_MODE_0:
mode_val = 0;
break;
case SPI_MODE_1:
mode_val = NPCM_PSPI_CTL1_SCIDL;
break;
case SPI_MODE_2:
mode_val = NPCM_PSPI_CTL1_SCM;
break;
case SPI_MODE_3:
mode_val = NPCM_PSPI_CTL1_SCIDL | NPCM_PSPI_CTL1_SCM;
break;
}
regtemp = ioread16(priv->base + NPCM_PSPI_CTL1);
regtemp &= ~(NPCM_PSPI_CTL1_SCM | NPCM_PSPI_CTL1_SCIDL);
iowrite16(regtemp | mode_val, priv->base + NPCM_PSPI_CTL1);
}
static void npcm_pspi_set_transfer_size(struct npcm_pspi *priv, int size)
{
u16 regtemp;
regtemp = ioread16(NPCM_PSPI_CTL1 + priv->base);
switch (size) {
case 8:
regtemp &= ~NPCM_PSPI_CTL1_MOD;
break;
case 16:
regtemp |= NPCM_PSPI_CTL1_MOD;
break;
}
iowrite16(regtemp, NPCM_PSPI_CTL1 + priv->base);
}
static void npcm_pspi_set_baudrate(struct npcm_pspi *priv, unsigned int speed)
{
u32 ckdiv;
u16 regtemp;
/* the supported rates are numbers from 4 to 256. */
ckdiv = DIV_ROUND_CLOSEST(clk_get_rate(priv->clk), (2 * speed)) - 1;
regtemp = ioread16(NPCM_PSPI_CTL1 + priv->base);
regtemp &= ~NPCM_PSPI_CTL1_SCDV6_0;
iowrite16(regtemp | (ckdiv << 9), NPCM_PSPI_CTL1 + priv->base);
}
static void npcm_pspi_setup_transfer(struct spi_device *spi,
struct spi_transfer *t)
{
struct npcm_pspi *priv = spi_master_get_devdata(spi->master);
priv->tx_buf = t->tx_buf;
priv->rx_buf = t->rx_buf;
priv->tx_bytes = t->len;
priv->rx_bytes = t->len;
if (!priv->is_save_param || priv->mode != spi->mode) {
npcm_pspi_set_mode(spi);
priv->mode = spi->mode;
}
if (!priv->is_save_param || priv->bits_per_word != t->bits_per_word) {
npcm_pspi_set_transfer_size(priv, t->bits_per_word);
priv->bits_per_word = t->bits_per_word;
}
if (!priv->is_save_param || priv->speed_hz != t->speed_hz) {
npcm_pspi_set_baudrate(priv, t->speed_hz);
priv->speed_hz = t->speed_hz;
}
if (!priv->is_save_param)
priv->is_save_param = true;
}
static void npcm_pspi_send(struct npcm_pspi *priv)
{
int wsize;
wsize = min(bytes_per_word(priv->bits_per_word), priv->tx_bytes);
priv->tx_bytes -= wsize;
if (priv->tx_buf) {
if (wsize == 1)
iowrite8(*priv->tx_buf, NPCM_PSPI_DATA + priv->base);
if (wsize == 2)
iowrite16(*priv->tx_buf, NPCM_PSPI_DATA + priv->base);
priv->tx_buf += wsize;
}
}
static void npcm_pspi_recv(struct npcm_pspi *priv)
{
int rsize;
u16 val;
rsize = min(bytes_per_word(priv->bits_per_word), priv->rx_bytes);
priv->rx_bytes -= rsize;
if (priv->rx_buf) {
if (rsize == 1)
val = ioread8(priv->base + NPCM_PSPI_DATA);
if (rsize == 2)
val = ioread16(priv->base + NPCM_PSPI_DATA);
*priv->rx_buf = val;
priv->rx_buf += rsize;
}
}
static int npcm_pspi_transfer_one(struct spi_master *master,
struct spi_device *spi,
struct spi_transfer *t)
{
struct npcm_pspi *priv = spi_master_get_devdata(master);
int status;
npcm_pspi_setup_transfer(spi, t);
reinit_completion(&priv->xfer_done);
npcm_pspi_enable(priv);
status = wait_for_completion_timeout(&priv->xfer_done,
msecs_to_jiffies
(NPCM_PSPI_TIMEOUT_MS));
if (status == 0) {
npcm_pspi_disable(priv);
return -ETIMEDOUT;
}
return 0;
}
static int npcm_pspi_prepare_transfer_hardware(struct spi_master *master)
{
struct npcm_pspi *priv = spi_master_get_devdata(master);
npcm_pspi_irq_enable(priv, NPCM_PSPI_CTL1_EIR | NPCM_PSPI_CTL1_EIW);
return 0;
}
static int npcm_pspi_unprepare_transfer_hardware(struct spi_master *master)
{
struct npcm_pspi *priv = spi_master_get_devdata(master);
npcm_pspi_irq_disable(priv, NPCM_PSPI_CTL1_EIR | NPCM_PSPI_CTL1_EIW);
return 0;
}
static void npcm_pspi_reset_hw(struct npcm_pspi *priv)
{
regmap_write(priv->rst_regmap, NPCM7XX_IPSRST2_OFFSET,
NPCM7XX_PSPI1_RESET << priv->id);
regmap_write(priv->rst_regmap, NPCM7XX_IPSRST2_OFFSET, 0x0);
}
static irqreturn_t npcm_pspi_handler(int irq, void *dev_id)
{
struct npcm_pspi *priv = dev_id;
u16 val;
u8 stat;
stat = ioread8(priv->base + NPCM_PSPI_STAT);
if (!priv->tx_buf && !priv->rx_buf)
return IRQ_NONE;
if (priv->tx_buf) {
if (stat & NPCM_PSPI_STAT_RBF) {
val = ioread8(NPCM_PSPI_DATA + priv->base);
if (priv->tx_bytes == 0) {
npcm_pspi_disable(priv);
complete(&priv->xfer_done);
return IRQ_HANDLED;
}
}
if ((stat & NPCM_PSPI_STAT_BSY) == 0)
if (priv->tx_bytes)
npcm_pspi_send(priv);
}
if (priv->rx_buf) {
if (stat & NPCM_PSPI_STAT_RBF) {
if (!priv->rx_bytes)
return IRQ_NONE;
npcm_pspi_recv(priv);
if (!priv->rx_bytes) {
npcm_pspi_disable(priv);
complete(&priv->xfer_done);
return IRQ_HANDLED;
}
}
if (((stat & NPCM_PSPI_STAT_BSY) == 0) && !priv->tx_buf)
iowrite8(0x0, NPCM_PSPI_DATA + priv->base);
}
return IRQ_HANDLED;
}
static int npcm_pspi_probe(struct platform_device *pdev)
{
struct npcm_pspi *priv;
struct spi_master *master;
struct resource *res;
unsigned long clk_hz;
struct device_node *np = pdev->dev.of_node;
int num_cs, i;
u32 csgpio;
int irq;
int ret;
num_cs = of_gpio_named_count(np, "cs-gpios");
if (num_cs < 0)
return num_cs;
pdev->id = of_alias_get_id(np, "spi");
if (pdev->id < 0)
pdev->id = 0;
master = spi_alloc_master(&pdev->dev, sizeof(*priv));
if (!master)
return -ENOMEM;
platform_set_drvdata(pdev, master);
priv = spi_master_get_devdata(master);
priv->master = master;
priv->is_save_param = false;
priv->id = pdev->id;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
priv->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(priv->base)) {
ret = PTR_ERR(priv->base);
goto out_master_put;
}
priv->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(priv->clk)) {
dev_err(&pdev->dev, "failed to get clock\n");
ret = PTR_ERR(priv->clk);
goto out_master_put;
}
ret = clk_prepare_enable(priv->clk);
if (ret)
goto out_master_put;
irq = platform_get_irq(pdev, 0);
if (irq < 0) {
dev_err(&pdev->dev, "failed to get IRQ\n");
ret = irq;
goto out_disable_clk;
}
priv->rst_regmap =
syscon_regmap_lookup_by_compatible("nuvoton,npcm750-rst");
if (IS_ERR(priv->rst_regmap)) {
dev_err(&pdev->dev, "failed to find nuvoton,npcm750-rst\n");
return IS_ERR(priv->rst_regmap);
}
/* reset SPI-HW block */
npcm_pspi_reset_hw(priv);
ret = devm_request_irq(&pdev->dev, irq, npcm_pspi_handler, 0,
"npcm-pspi", priv);
if (ret) {
dev_err(&pdev->dev, "failed to request IRQ\n");
goto out_disable_clk;
}
init_completion(&priv->xfer_done);
clk_hz = clk_get_rate(priv->clk);
master->max_speed_hz = DIV_ROUND_UP(clk_hz, NPCM_PSPI_MIN_CLK_DIVIDER);
master->min_speed_hz = DIV_ROUND_UP(clk_hz, NPCM_PSPI_MAX_CLK_DIVIDER);
master->mode_bits = SPI_CPHA | SPI_CPOL;
master->dev.of_node = pdev->dev.of_node;
master->bus_num = pdev->id;
master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
master->transfer_one = npcm_pspi_transfer_one;
master->prepare_transfer_hardware =
npcm_pspi_prepare_transfer_hardware;
master->unprepare_transfer_hardware =
npcm_pspi_unprepare_transfer_hardware;
master->num_chipselect = num_cs;
for (i = 0; i < num_cs; i++) {
csgpio = of_get_named_gpio(np, "cs-gpios", i);
if (csgpio < 0) {
dev_err(&pdev->dev, "failed to get csgpio#%u\n", i);
goto out_disable_clk;
}
dev_dbg(&pdev->dev, "csgpio#%u = %u\n", i, csgpio);
ret = devm_gpio_request_one(&pdev->dev, csgpio,
GPIOF_OUT_INIT_HIGH, DRIVER_NAME);
if (ret < 0) {
dev_err(&pdev->dev,
"failed to configure csgpio#%u %u\n"
, i, csgpio);
goto out_disable_clk;
}
}
/* set to default clock rate */
npcm_pspi_set_baudrate(priv, NPCM_PSPI_DEFAULT_CLK);
ret = devm_spi_register_master(&pdev->dev, master);
if (ret)
goto out_disable_clk;
pr_info("NPCM Peripheral SPI %d probed\n", pdev->id);
return 0;
out_disable_clk:
clk_disable_unprepare(priv->clk);
out_master_put:
spi_master_put(master);
return ret;
}
static int npcm_pspi_remove(struct platform_device *pdev)
{
struct npcm_pspi *priv = platform_get_drvdata(pdev);
npcm_pspi_reset_hw(priv);
clk_disable_unprepare(priv->clk);
return 0;
}
static const struct of_device_id npcm_pspi_match[] = {
{ .compatible = "nuvoton,npcm750-pspi", .data = NULL },
{}
};
MODULE_DEVICE_TABLE(of, npcm_pspi_match);
static struct platform_driver npcm_pspi_driver = {
.driver = {
.name = DRIVER_NAME,
.of_match_table = npcm_pspi_match,
.owner = THIS_MODULE,
},
.probe = npcm_pspi_probe,
.remove = npcm_pspi_remove,
};
module_platform_driver(npcm_pspi_driver);
MODULE_DESCRIPTION("NPCM peripheral SPI Controller driver");
MODULE_AUTHOR("Tomer Maimon <tomer.maimon@nuvoton.com>");
MODULE_LICENSE("GPL v2");